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排序方式: 共有301条查询结果,搜索用时 12 毫秒
111.
Vassilis Christofides Paul Ainsworth Senol Ìbanolu Frances Gomes 《Molecular nutrition & food research》2004,48(1):61-64
Response surface methodology was used to analyze the effect of screw speed (200–280 rpm), feed moisture (13.0–17.0%, wet basis), and curry powder (6.0–9.0%) on the bulk density, lateral expansion, and firmness of maize‐based extruded snack with curry powder. Regression equations describing the effect of each variable on the responses were obtained. Responses were most affected by changes in feed moisture followed by screw speed and curry powder (p < 0.05). Lateral expansion increased linearly as the amount of curry powder added was increased whereas a quadratic increase was obtained in lateral expansion with decreasing feed moisture. The firmness of samples was increased with an increase in feed moisture. The bulk density of samples was increased with increasing feed moisture and screw speeds. Radial expansion was found to be a better index to measure the physical properties of the extruded product indicated by a higher correlation coefficient. 相似文献
112.
Bratsas C Koutkias V Kaimakamis E Bamidis PD Pangalos GI Maglaveras N 《Computer methods and programs in biomedicine》2007,88(1):39-51
In this paper, an ontology-based system (KnowBaSICS-M) is presented for the semantic management of Medical Computational Problems (MCPs), i.e., medical problems and computerised algorithmic solutions. The system provides an open environment, which: (1) allows clinicians and researchers to retrieve potential algorithmic solutions pertinent to a medical problem and (2) enables incorporation of new MCPs into its underlying Knowledge Base (KB). KnowBaSICS-M is a modular system for MCP acquisition and discovery that relies on an innovative ontology-based model incorporating concepts from the Unified Medical Language System (UMLS). Information retrieval (IR) is based on an ontology-based Vector Space Model (VSM) that estimates the similarity among user-defined MCP search criteria and registered MCP solutions in the KB. The results of a preliminary evaluation and specific examples of use are presented to illustrate the benefits of the system. KnowBaSICS-M constitutes an approach towards the construction of an integrated and manageable MCP repository for the biomedical research community. 相似文献
113.
Vassilis J. Tsotras Vidyadhar Phalke Anil Kumar B. Gopinath 《Journal of Network and Systems Management》1999,7(2):149-176
In many network management applications, likepost-mortem fault analysis or performance trendsprofiling, it is advantageous to have the ability toview the state of the network as it was at some time in the past. To support such Temporal Views anefficient data organization, or access method, is neededfor storing and updating network related data (as thenetwork evolves over time) and for retrieving requested past network states. For applications where thenetwork manager is not interested in the full (and maybetoo large) snapshot of a past network state it is usefulif partial state snapshots can be extracted quickly. It is thus of particular interest toconstruct an access method that can efficiently supportPartial Temporal Views. Efficiency implies that arequested partial temporal view should be constructed directly, without first computing the elaboratefull temporal view. In this paper we present a newaccess method (called the Neighbor History Index) forthis problem. One of the advantages of this method is that the update processing is independent ofthe evolution size (the total number of changes in theevolution). In addition, our method uses a small diskspace overhead. We then present a general framework for organizing time-evolving network data. Ourframework distinguishes between flat and hierarchicalevolutions and subsequently between flat andhierarchical temporal views. We also provide a way toefficiently construct temporal views on hierarchicalevolutions. This paper shows that supporting temporalviews on flat or hierarchical evolutions is notexpensive: our solutions use small space overhead, havesmall updating and compute temporal viewsfast. 相似文献
114.
Screening (100%-inspection) is a common practice in quality engineering. Traditional screening procedures seek upper and lower specification limits for a quality characteristic associated with some product, such that the total quality cost per item is minimized. This practice ignores the effect of parts rejection on product lead times, inventory carrying costs, shortage costs, throughput, and, eventually, total profit rate of the system. In this paper, a single-stage production system is considered and two control policies arc determined jointly with the inspection plans. Numerical experiments indicate that such co-ordinated policies achieve a better performance than independently determined quality and production control policies 相似文献
115.
Rahul Chattergy Vassilis L. Syrmos Pradeep Misra 《Circuits, Systems, and Signal Processing》1996,15(5):631-648
In this paper we examine order reduction of parabolic systems using modal truncation. The parabolic distributed system is first approximated using the Galerkin method. The system matrices have a special structure that allows us to find the approximate spectrum of the parabolic system. To do this we compute approximate inverses of tridiagonal, diagonally dominant symmetric matrices. The approximation leads to algorithms of orderO(n), as opposed to traditional algorithms of orderO(n), wheren is the order of the system. Finally, an example is presented to illustrate the proposed algorithm.This research was supported by the National Science Foundation under contract NCR-9210408, by the Advanced Research Programs Agency under contract MDA-972-93-1-0032, and by the University of Hawaii Research Council Funds. 相似文献
116.
Koutsioulis D Wang E Tzanodaskalaki M Nikiforaki D Deli A Feller G Heikinheimo P Bouriotis V 《Protein engineering, design & selection : PEDS》2008,21(5):319-327
Psychrophilic alkaline phosphatase (AP) from the Antarctic strain TAB5 was subjected to directed evolution in order to identify the key residues steering the enzyme's cold-adapted activity and stability. A round of random mutagenesis and further recombination yielded three thermostable and six thermolabile variants of the TAB5 AP. All of the isolated variants were characterised by their residual activity after heat treatment, Michaelis-Menten kinetics, activation energy and microcalorimetric parameters of unfolding. In addition, they were modelled into the structure of the TAB5 AP. Mutations which affected the cold-adapted properties of the enzyme were all located close to the active site. The destabilised variants H135E and H135E/G149D had 2- and 3-fold higher kcat, respectively, than the wild-type enzyme. Wild-type AP has a complex heat-induced unfolding pattern while the mutated enzymes loose local unfolding transitions and have large shifts of the Tm values. Comparison of the wild-type and mutated TAB5 APs demonstrates that there is a delicate balance between the enzyme activity and stability and that it is possible to improve the activity and thermostability simultaneously as demonstrated in the case of the H135E/G149D variant compared to H135E. 相似文献
117.
The depth-profiles of accelerated aged triterpenoid dammar and mastic varnishes, which had been uncovered by optimized KrF excimer laser ablation (248 nm, 25 ns), were examined by ultraviolet-visible (UV/VIS) spectrophotometry and attenuated total reflection (ATR) Fourier transform infrared (FT-IR) spectroscopy. The results reflect both the optical properties at the bulk (UV/VIS) and the surface (ATR/FT-IR) and establish the presence of degradation gradients across the depth of the degraded natural resin films. It is demonstrated that the UV part of the ambient radiation is absorbed by the deteriorated surface and that the optical densities of the aged varnish decrease as a function of depth. The absorbed UV wavelengths at the surface and the depth-wise reduction of light intensity result in a depth-dependent decrease in carbonyl absorbance and an increase in C-H bending vibration modes of methylene species pointing to structural modification in the triterpenoid mixture across depth. 相似文献
118.
Georgios E. Vekris Vassilis Syrris Christos K. Manavis Wamadeva Balachandran Marios Hadjinicolaou Nikolaos N. Kyriakoudis 《Circuits, Systems, and Signal Processing》2013,32(6):2667-2681
This work presents applications of an inductive topological approach in the calculation of the transfer function of a cascading network control system. The method provides a very versatile and effective way of counting all the graphs that contribute and of translating them into their algebraic contribution. The contributing graphs are very simple and reflect the morphology of the original control system signal flow graph. Application of the method and results are presented for an n-cell RC network. We derive an analytical formula relating ω(3 dB) to the filter size (n) and R j C j (j=1,2,…,n). This formula can be used for designing preset frequency range self-loaded LP filters by varying their size. We also derive general expressions for the sensitivities which we use to observe a sensitivity-insensitivity filter transition for various frequency ranges, relaxation times, and, most importantly, filter sizes. 相似文献
119.
Stavros Lalas Olga Gortzi Vasilios Athanasiadis Eftalia Dourtoglou Vassilis Dourtoglou 《Journal of the American Oil Chemists' Society》2012,89(12):2253-2258
This work was dedicated to reporting the full chemical and physical characterisation of Crambe abyssinica Hochst. seed oil. The oil from the seeds was extracted using n-hexane. The seeds contain about 30?% oil. Density, refractive index, colour, smoke point, viscosity, acidity, saponification value, iodine value, fatty acid methyl esters, the relative position of fatty acids in C1 and C3 carbon glycerol, sterols, tocopherols, peroxide value, $ \mathop E\nolimits_{{1{\text{cm}}}}^{1\,\% } $ at 232?nm, and the susceptibility to oxidation measured by the Rancimat method were determined. The oil was found to contain high levels of unsaturated fatty acids, especially C22:1 (63.77?%). The dominant saturated acid was C22:0 (2.14?%). The oil was also found to contain high levels of β-sitosterol (51.93?%), campestanol (21.98?%), and brassicasterol (12.35?%). α-, γ-, and δ-Tocopherols were detected up to levels of 7.67, 125.04, and 3.99?mg/kg, respectively. The induction period (at 110?°C and 20?l/h) of the oil was 8.83?h. The relative position of fatty acids in C1 and C3 position was as follows: linoleic 0.45?%, oleic 8.84?%, and erucic 90.72?%. The thermal profile of the oil presented a single peak at ?20.94?°C. 相似文献
120.
Does inequality matter for regional growth? This paper addresses this question, using regionally aggregated microeconomic data for more than 100,000 individuals over a period of 6 years. The aim is to examine the relationship between income and educational distribution and regional economic growth in western Europe. Our results indicate that, given existing levels of inequality, an increase in a region’s income and educational inequality has a significant positive association with subsequent economic growth. Educational achievement is positively correlated with economic growth, but the impact of initial income levels is unclear. Finally, the results suggest that inequalities in educational attainment levels matter more for economic performance than average educational attainment. The above findings are not only robust to the definition of income distribution, but also across inequality measurements. 相似文献